PubMedPubMed Central (PMC) is a free digital repository that archives
publicly accessible full-text scholarly articles that have been
published within the biomedical and life sciences journal literature.
As one of the major research databases within the suite of resources
that have been developed by the National Center for Biotechnology
Information (NCBI),
PubMedPubMed Central is much more than just a document
repository. Submissions into PMC undergo an indexing and formatting
procedure which results in enhanced metadata, medical ontology, and
unique identifiers which all enrich the
XMLXML structured data for each
article on deposit.[1] Content within PMC can easily be interlinked to
many other NCBI databases and accessed via
EntrezEntrez search and retrieval
systems, further enhancing the public's ability to freely discover,
read and build upon this portfolio of biomedical knowledge.[2]
PubMedPubMed Central should not be confused with PubMed. These are two very
different services at their core.[3] While
PubMedPubMed is a searchable
database of biomedical citations and abstracts, the full-text article
referenced in the
PubMedPubMed record will physically reside elsewhere.
(Sometimes in print, sometimes online, sometimes free, sometimes
behind a toll-wall accessible only to paying subscribers). PubMed
Central is a free digital archive of articles, accessible to anyone
from anywhere via a basic web browser. The full text of all PubMed
Central articles is free to read, with varying provisions for reuse.
As of December 2016[update], the PMC archive contained over 4.1
million articles,[4] with contributions coming directly from
publishers or authors depositing their own manuscripts into the
repository per the
NIHNIH Public Access Policy. Older data shows that
from Jan 2013 – Jan 2014 author-initiated deposits exceeded 103,000
papers during this 12-month period.[5] PMC also identifies about 4,000
journals which now participate in some capacity to automatically
deposit their published content into the PMC repository.[6] Some
participating publishers will delay the release of their articles on
PubMedPubMed Central for a set time after publication, this is often
referred to as an "embargo period", and can range from a few months to
a few years depending on the journal. (Embargoes of six to twelve
months are the most common). However,
PubMedPubMed Central is a key example
of "systematic external distribution by a third party"[7] which is
still prohibited by the contributor agreements of many publishers.

Adoption[edit]
See also:
NIHNIH Public Access Policy
Launched in February 2000, the repository has grown rapidly as the NIH
Public Access Policy is designed to make all research funded by the
National Institutes of HealthNational Institutes of Health (NIH) freely accessible to anyone, and,
in addition, many publishers are working cooperatively with the
NIHNIH to
provide free access to their works. In late 2007, the Consolidated
Appropriations Act of 2008 (H.R. 2764) was signed into law and
included a provision requiring the
NIHNIH to modify its policies and
require inclusion into
PubMedPubMed Central complete electronic copies of
their peer-reviewed research and findings from NIH-funded research.
These articles are required to be included within 12 months of
publication. This is the first time the US government has required an
agency to provide open access to research and is an evolution from the
2005 policy, in which the
NIHNIH asked researchers to voluntarily add
their research to
PubMedPubMed Central.[8]
A UK version of the
PubMedPubMed Central system, UK
PubMedPubMed Central (UKPMC),
has been developed by the
Wellcome TrustWellcome Trust and the
British LibraryBritish Library as
part of a nine-strong group of UK research funders. This system went
live in January 2007. On 1 November 2012, it became Europe PubMed
Central. The Canadian member of the
PubMedPubMed Central International
network,
PubMedPubMed Central Canada, was launched in October 2009.
The
National Library of MedicineNational Library of Medicine "NLM Journal Publishing Tag Set"
journal article markup language is freely available.[9] The
Association of Learned and Professional Society PublishersAssociation of Learned and Professional Society Publishers comments
that "it is likely to become the standard for preparing scholarly
content for both books and journals".[10] A related DTD is available
for books.[11] The
Library of CongressLibrary of Congress and the
British LibraryBritish Library have
announced support for the NLM DTD.[12] It has also been popular with
journal service providers.[13]
With the release of public access plans for many agencies beyond NIH,
PMC is in the process of becoming the repository for a wider variety
of articles.[14] This includes NASA content, with the interface
branded as "PubSpace".[15][16]
Technology[edit]
Articles are sent to
PubMedPubMed Central by publishers in
XMLXML or SGML,
using a variety of article DTDs. Older and larger publishers may have
their own established in-house DTDs, but many publishers use the NLM
Journal Publishing DTD (see above).
Received articles are converted via
XSLTXSLT to the very similar NLM
Archiving and Interchange DTD. This process may reveal errors that are
reported back to the publisher for correction. Graphics are also
converted to standard formats and sizes. The original and converted
forms are archived. The converted form is moved into a relational
database, along with associated files for graphics, multimedia, or
other associated data. Many publishers also provide
PDFPDF of their
articles, and these are made available without change.[17]
BibliographicBibliographic citations are parsed and automatically linked to the
relevant abstracts in PubMed, articles in
PubMedPubMed Central, and
resources on publishers' Web sites.
PubMedPubMed links also lead to PubMed
Central. Unresolvable references, such as to journals or particular
articles not yet available at one of these sources, are tracked in the
database and automatically come "live" when the resources become
available.
An in-house indexing system provides search capability, and is aware
of biological and medical terminology, such as generic vs. proprietary
drug names, and alternate names for organisms, diseases and anatomical
parts.
When a user accesses a journal issue, a table of contents is
automatically generated by retrieving all articles, letters,
editorials, etc. for that issue. When an actual item such as an
article is reached,
PubMedPubMed Central converts the NLM markup to
HTMLHTML for
delivery, and provides links to related data objects. This is feasible
because the variety of incoming data has first been converted to
standard DTDs and graphic formats.
In a separate submission stream, NIH-funded authors may deposit
articles into
PubMedPubMed Central using the
NIHNIH Manuscript Submission
(NIHMS). Articles thus submitted typically go through
XMLXML markup in
order to be converted to NLM DTD.
Reception[edit]
Reactions to
PubMedPubMed Central among the scholarly publishing community
range between a genuine enthusiasm by some,[18] to cautious concern by
others.[19] While PMC is a welcome partner to open access publishers
in its ability to augment the discovery and dissemination of
biomedical knowledge, that same truth causes others to worry about
traffic being diverted from the published version-of-record, the
economic consequences of less readership, as well as the effect on
maintaining a community of scholars within learned societies.[20]
Libraries, universities, open access supporters, consumer health
advocacy groups, and patient rights organizations have applauded
PubMedPubMed Central, and hope to see similar public access repositories
developed by other federal funding agencies so to freely share any
research publications that were the result of taxpayer support.[21]
The Antelman study of open access publishing found that in philosophy,
political science, electrical and electronic engineering and
mathematics, open access papers had a greater research impact.[22] A
randomised trial found an increase in content downloads of open access
papers, with no citation advantage over subscription access one year
after publication.[23]
The change in procedure has received criticism.[24] The American
Physiological Society has expressed reservations about the
implementation of the policy.[25]
PMCID[edit]
The PMCID (
PubMedPubMed Central identifier), also known as the PMC reference
number, is a bibliographic identifier for the
PubMedPubMed Central database,
much like the
PMIDPMID is the bibliographic identifier for the PubMed
database. The two identifiers are distinct however. It consists of
"PMC" followed by a string of seven numbers. The format is:[26]

PMCID: PMC1852221

Authors applying for
NIHNIH awards must include the PMCID in their
application.
See also[edit]

^ Beck, Jeff. "Report from the Field:
PubMedPubMed Central, an XML-based
Archive of Life Sciences Journal Articles". Proceedings of the
International Symposium on
XMLXML for the Long Haul: Issues in the
Long-term Preservation of XML. doi:10.4242/BalisageVol6.Beck01.
^ NCBI Handbook:
PubMedPubMed Central. Chris Maloney, Ed Sequeira,
Christopher Kelly, Rebecca Orris, and Jeffrey Beck Dec 2013
^ MEDLINE, PubMed, and PMC (
PubMedPubMed Central): How are they different?
^ "Openness by Default", Inside Higher Ed, 16th January 2017.
^
NIHNIH Manuscript Submission Statistics
^ PubMedCentral
^
https://www.researchgate.net/file.PostFileLoader.html?id=55e4a08d614325a0dc8b4593&assetKey=AS%3A273846177861632%401442301424139
^ "Public access to
NIHNIH research made law". Science Codex. 2007.
Archived from the original on 4 March 2016. Retrieved 6 November
2013.
^ "Journal Publishing Tag Set". National Center for Biotechnology
Information. Retrieved 6 November 2013.
^ French, Diane (4 August 2006). "ALPSP Technology Update: A Standard
XMLXML Document Format: The case for the adoption of NLM DTD". ALPSP.
Retrieved 6 November 2013.
^ NLM-NCBI Book Tag Set
^ "News from the Library of Congress". Library of Congress. 19 April
2006. Retrieved 6 November 2013.
^ Inera NLM DTD Resources
^ Public Access Plans of U.S. Federal Agencies
^ Public Access to Results of NASA-funded Research
^ PubSpace
^ NLM Journal Archiving and Interchange Tag Suite, National Center for
Biotechnical Information, National Library of Medicine
^ PLOS Applauds Congress for Action on Open Access
^ ACS Submission to the Office of Science and Technology Policy
Request for Information on Public Access to Peer-Reviewed Scholarly
Publications Resulting from Federally Funded Research
^ Davis PM. The effect of public deposit of scientific articles on
readership. Physiologist. 2012 Oct;55(5):161, 163-5
^ Autism Speaks Announces New Policy to Give Families Easy, Free
Access to Key Research Findings
^ Kristin Antelman (September 2004). "Do Open-Access Articles Have a
Greater Research Impact?". College & Research Libraries 65(5).
pp. 372–382. and summarized by C&RL News
^
Open accessOpen access publishing, article downloads, and citations: randomised
controlled trial
^ C&RL News: Scholarly Communication in Flux: Entrenchment and
Opportunity Kate Thomes, Science & Technology Libraries 22, no.
3/4 (220): 104 "Many faculty see the current system of scholarly
communication as an effective, known, and reliable system that is not
broken and therefore does not need to be fixed".
^ The American Physiological Society "Although the American
Physiological Society (APS) supports the principle of public access,
the
NIHNIH approach is a mallet rather than a scalpel. It is likely to
harm publishers, which will in turn harm the dissemination of science
through the literature".
^ "Include PMCID in Citations publicaccess.nih.gov".
publicaccess.nih.gov. Retrieved 2017-07-01.